During his free hours, Khalil would practice and sketch human figures, studying the forms and structure. This work displays how thoughtfully Khalil considers each figure's postures and gestures. His sketches of the East Coast communities reveal his fascination for the human figure. Khalil graduated with a National Diploma of Design in Fine Arts at the prestigious St. Martin's School of Art and Design in London in 1964 (post-graduate in 1965). Khalil was a co-founder of the Malaysian Watercolour Society and had his first double solo of London works and Malaysian batiks at Samat Art Gallery, Kuala Lumpur in 1970. That year, he also had a solo exhibition in Indonesia, the first Malaysian to have done so. He has participated in numerous solo and group exhibitions in Malaysia, Singapore, Indonesia, Switzerland, and his works have been collected by the National Art Gallery Malaysia, the National Museum in Singapore, Fukuoka Museum of Art in Japan, New South Wales Museum of Art in Sydney and the Royal National Art Gallery of Jordan.